might a kind person please explain the relationship between the final airflow minimum on the idle tab and how it relates to the vve. trying to dial in my idle. thank you
might a kind person please explain the relationship between the final airflow minimum on the idle tab and how it relates to the vve. trying to dial in my idle. thank you
Not entirely sure I understand where you're going with the question, but at it's basics, it's airflow. It should always be lowest around your idle rpms and go up from there. If it's not, then you need to adjust your throttle stop settings. You don't want it so high that it causes "self cruise" off idle. VE and MAF need to be dialed in to agree with one another. Then you can fine tune or tweak idle controls from there.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
I used this method to set minimum final air flowOriginally Posted by poulina
https://forum.hptuners.com/showthrea...BoCO48QAvD_BwE
Also don't forget to change your start up airflow table to suit your application as it uses this table for the first 4 seconds on startup.
I was experiencing a big flare on startup until I reduced these numbers.
assuming my maf & vve are dialed in, i should be using those values logged in the scanner determine my airflow minimum values at each rpm in the column axis?
i'm new to this so i may not be correct in saying this - but thats the gist of what i've figured out. you can create a histogram to log it specifically so you don't have to watch the numbers wiz by
u dont have to do it to the entire rev range, usually just idle rpm then set the highest rpm to like 20-30 and just populate between, if its too high the rpm will hang or not decel when u let off or change gears
No direct relationship.
I've always looked at it as final airflow minimum is the carb screw base idle warm and the VVE was more of the mixture control screw for idle and jets for fueling. emulsion tubes and power valve as P.E.
This is the way I understand it too.
Min Final Airflow is commanding the throttlebody opening. We are telling it in grams/sec, but the ECM has to determine the actual opening based on the ETC scalar, effective area, baro, ECT, etc. Then it determines how far to open the throttle blade.
Fueling is then determined by MAF and VVE.
A standard approach will give you standard results.
My Tuning Software:
VVE Assistant [update for v1.5]
MAF Assistant
EOIT Assistant
Minimum final airflow doesn't affect the throttle unless the engine is riding on that table. Gen4+ base throttle position command is determined by a back-calculated airflow requested by the torque model and augmented by throttle follower and idle adaptive airflow.
Interesting.
In my extremely limited experience Final Min has a major impact, but maybe I'm just riding the table.
I'm sure this is a very deep rabbit hole but... I'm curious.
When changing a cam the engine torque curve obviously changes.
Would it be ideal to match the torque model coefficients to the new torque curve, or is that serious overkill?
I would guess that the Airflow Baro tables do a majority of the work, especially at idle..
but how are the tables factored in and is the full torque model formula even known/available?
Jesus!!! You shouldn't say things like that. I mean for crying out loud 3 voodoo terms put together..... OK, to be honest I'm not sure on the CORRECT way to tune these myself, but the way I do it seems to work out well or at least it seems to solve problems and make customers happy. Any chance at all you could explain how they need to be setup or done? I always try to leave - what I believe I'm leaving as safeties in them and work the adaptives for smooth transitions to and from idle. Is there a general rule of thumb for some of these settings?
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
Reading in between the lines, we tweak the torque model a widdle bit and make a small change to the airflow baro table(s).
smokeshow, was I close? I'm not ready to disassemble this processor yet, still balls deep in my T43!
You out there Alvin? Have you spent any time on working out the idle functions?
Hopefully when you're done on your end we can get the torque models a whole lot closer. So far testing has shown the map table changes using an older version to be doing pretty good even if they are global changes.
Last edited by GHuggins; 01-31-2024 at 12:38 AM.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
Sounds like a plan
Had a dig, that's a no on the baro tables for idle. Those tables are for driver request torque.
There is a painfully explicit method of calculating almost all of this. Gen4+...it all begins with the torque models. If you can manage to get them close, everything else becomes much easier.
I was wondering what you meant.
does the min airflow correspond to the reported g/s airflow or actual TB blade/area % ? as the g/s can be fudged by scaling airflow but the TB idle % stays the same the min airflow should only use the TB % to remain more stable ?
Dynamic airflow, yes. Ideally, dynamic air represents covers both the measured airflow and where throttle transients cause the throttle airflow and measured airflow to diverge. If you scale the airflow, that doesn't hold true though. Airflow will always defer to steady state measurement (MAF) when the throttle is steady, so min airflow will follow the scaled value at steady idle. The throttle flow model and MAP torque model have some ability to learn in errors, so that can eat some of the discrepancy if you scale the airflow.
ok thanks, the joys of a slightly scaled tune, light clutch/flywheel and early e38 where the only idle feedback i get is the adaptive spark, keeps things trickyafter full build i left the min airflow as it was with old setup thinking as the TB % was the same the reading will be ok being higher then the reported min g/s, ill have to try it lower under the idle g/s see how it goes
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